Question

A pendulum of mass 5.0 ???????? hangs in equilibrium. A frustrated student walks up to it and kicks the bob with a horizontal force of 30.0 ????. What is the maximum angle of displacement of the swinging pendulum? How long does the pendulum have to be to have a period of 5.0 ????????co?????????????

Answer 1

Answer:

a. 37.75°

b. 6.21 m

Explanation:

a. The horizontal force acting on a pendulum bob is given as:

F = mgsinθ

where m = mass of bob

g = acceleration due to gravity

θ = angle string makes with the vertical or angle of displacement

Making θ subject of formula, we have:

θ = $sin^{-1}(\frac{F}{mg} )$

θ = $sin^{-1} (\frac{30}{5*9.8})$

θ = 37.75°

The maximum angle of displacement is 37.75°

b. Period of a pendulum is given as:

$T = 2\pi\sqrt{ \frac{L}{g} }$

where L = length of string

Therefore, making L subject of formula:

$L = \frac{gT^2}{4\pi^2}$

$L = \frac{9.8 * 5^2}{4\pi^2} \\\\\\L = 6.21 m$

The string holding the pendulum has to be 6.21 m long.